Question

Find out the following squares by using the identities:
$(0.4a-0.5b{)}^2$

Answer 1

We know $(x-y{)}^2=x^2-2xy+y^2$

Here $x=0.4a,y=0.5b$

By using this identity, we get

$(0.4a-0.5b{)}^2$

$=(0.4a{)}^2+(0.5b{)}^2-2\times 0.5b\times 0.4a$

$=0.16a^2+0.25b^2-0.4ab$

This is the required answer.